Machine for making bituminous emulsion



Jan. 22, i935. L, R, `MacKENZlE '1,988,743

MACHINE FOR MAKING BITUMINoUs EMULsIoN Filed'March 2, 1951 v5Sheets-sheet 1 Jan.'22, 1935. L. R. MacKENziE 1,988,743

MACHINE FOR MAKING BITUMINOUS EMULSION Fil'ed March 2, 1931 3Sheets-.Shet 2 Jan. 22, 1935o L. R. MacKENzlE 1,988,743

MACHINE FOR MAKING BITUMlNOS EMLSION i Filed March 2, 1931 3Sheets-'Sheet 3 @iff ` I li lf JIU l5 which is then inverted to form asecondary intertially conical ooaoting Surfaces are employed, one i '35ing aliqueous emulsion of a bituminous substance Figure 3 iS a SimilarVieW Showing a further no Patented Jan.. 122,` 1935 l UNITED STATESPATENT OFFICE MACHINE FOR MAKING BITUM'INOUS EMULSION Leon R.-MacKenzie, Des Moines, Iowa, assignor to L. R. MacKenzie Incorporated,Tulsa, Okla., a corporation of Delaware Application March 2, 1931,serial No. l519417 11 claims. (01.134-1) The purpose and aim of thisinvention is to Figure 2 is a longitudinal section of the same. providea machine for making a stablellqueous As shown particularly in thisview, this form of emulsion of a bituminous substance either liquid themachine employs two substantially cylindrior semi-liquid or capable ofbecoming liquid, such cal surfaces, one being arranged for rotationwithas asphalt, and particularly a machine adapted in the other andbeing slightly tapered to formf 5 to the process covered by myco-pending applian elongated converging annular space, one cation, ledOctober 30, 1930, Serial No. 492,169, member being adjustablelongitudinally with renow Patent Number 1,795,226. lation to the otherso as to provide meansfor This machine is peculiarly adapted forcarryregulating the spacing of the surfaces and the l0 ing out acontinuous process of succession of resultant neness of the emulsionDrodueed- 10 steps beginning with the introduction of hot liq- Figure 3is 'a transverse section on the line 3 3 ueous bitumen and anemulsifying agent, at propof Figure 2- er temperatures, to a closedchamber and form- Figure 4iS a vlongitudinal Section illustrating e inga primary bitumen external phase emulsion dilerent form of machine inwhich tWO Substannel phase emulsion, The Secondary emulsion is conicalmember being arranged for rotation withthen subjected to a stretching,sub-dividing and inthe other. This form of the machine also emrollingoperation betweenelongated and convergbodies o jacket for live Steam.whereby the ining relatively moving surfaces, whereby the coarse teriorof the machine muy be heated. emulsion is changed to one of nner form,'and a, Figure 5 is a cross section on the line 5 5 of 2o variation o!sizes of particles is produced. There- Figure 4- ater, the fine tertiaryemulsion is subjected to Figure 6 iS a CroSS Seotion 0n the line 6-6 0fcentrifugal action to remove air bubbles and to Figure e. reduce it frome. fcamy tc e more fluid state, as Figure '1 is a longitudinal sectionillustrating e well as to increase the thoroughness of the mixingPortion 0f emaehine Somewhat Similar to that 2li andthe completeness ofdispersion. Shown in Figure 4, but modified With respect to l Includedwithin the scope of this invention is the mixing chamber or zone offormation of the the object of adjustability of one of the coacting'primary emulsion, this machine being equipped surfaces relative to theother for the purpose of with an interrupted spiral blade mounted forchanging the spacing between said surfaces and rotation in the elongatedchamber, the initial to thereby regulating the size of the particles ofportion of Said blade noting es e wiping and bitumen in the resultingemulsion. equalizing member and the longer terminal por- Another objectof the invention is to provide tion acting eS an egitating and emulsionodvenoan improved construction for a machine for malcing means.

such as asphalt, which emulsion will be suflicientmodified form ofmachine having a different form ly stable so that it can be handled,stored, and of o Spiral rotary member Which Combines the used underordinary conditions. functions of an agitating member and a grindingWith these and other objects in View my invenmember in coaction with thewalls of a chamber 4U tion consists in the construction, arrangementwhich graduulllr iIlCreeSeS in diameterand combination of the variousparts of my de- Figure 9 is a cross section of a machine of still vice,whereby the objects contemplated are atfurther modified form in whichthe rotary memtained, ashereinafter more fully set forth, pointed ber iseccentrically mounted within the chamber out in my claims, andillustrated in the accom for producing a converging eiiectv of the spacepanying drawings. Although the invention is between the coastingsurfaces. This machine also 45 susceptible of a variety of embodimentsit is unembodies a different means for producing centrifnecessary tofully describe and illustrate al1 posugal action with respect to thecompleted emul- 4sible forms in order to give a-full understanding ofsion.

the invention both from its structural and func- Figure 10 is aperspective view illustrating a tional standpolnts. Accordingly, l haveillustratmodified form of frusto-conical arbor grinding 50 Yedseveralpreferred and'desirable embodiments member. This member is ofthe same general of the invention in the Aaccompanying drawings, type asthe corresponding member of the machine in which:- n illustrated inFigure 4, but is modified with re- Figure 1 is a perspective view of amachine emspect to a series of tapering grooves extending bodyingoneform of my invention. Vlongitudinally of its surface. f 555 Figure 11 isa detail longitudinal section of portion of the arbor grinding memberillustra in Figure 10, and the surface with which it coacts. This viewillustrates particularly the fact that the 'tapering groove formed inthe surface of the arbor grinding member affords a different degree ofconvergence relative to the coactlng surface, than is afforded by thegeneral surface .of the arbor grinding member with respect to saidcoacting surface.

Various kinds and forms of emulsions may be made with machines embodyingthe present invention, and with bitumen of any desired state of hardnessor ductility. The emulsions may be made with any reasonable andpractical relative volumes of'bitumen and the emulsifying agent, whichwill hereinafter be referred to as emulsiner. A further advantageresides in the speed and economy of production which may be had. l

I have found that a very important characteristic of the machine isembodied in the use of two closely approximated surfaces of elongatedcharacter or extent, at least one of which is rotated relative to theother, and which preferably converge toward the outlet of the spacebetween them. These surfaces, which may or may not be serrated orotherwise deformed or roughened, act to stretch, sub-divide and roll theparticles of bitumen into progressively finer form and also act toincrease the dissemination, dispersion and diffusion of the bituminousparticles through the emulsifier and thus produce the desired type ofemulsion.

'I'he spaced surfaces may be of dilerent shapes and formations and maybe embodied in machines of varied constructions. In the accompanyingdrawings I have illustrated a number of different types of machines asexamples of different embodiments of my invention.

In the construction according to Figures l, 2 and 3, I have employed thenumeral 10 to designate a suitable base upon which is mounted or formeda suitable casing member 12 which preferably is substantiallycylindrical.

One end of the casing is formed by a separate plate 14 which is ttedsnugly to the member 12 and secured in place in any suitable manner, asby cap screws 16.

The rigid end wall of the casing member 12 is formedwith a tubularextension 18 of less diameter than and communicating with the interiorof the casing.

The tubular extension 18 is interiorly threaded and a sleeve 20 isadjustably mounted therein and extends within the inner casing member12. The sleeve 20 is open at its inner end and is formed at its outerend with an angular wrenchreceiving or capportion 22 by means of whichit may be adjusted within the tubular extension 18 and the wall of thecasing.

The tubular extension 18 preferably is split longitudinally on one sideby means of a slot or kerf 24 opening to its outer end and is formedwith a pair of ears 26 and 28 on opposite sides of the outer end of saidkerf.

A clamping lever 30 is provided and is formed with a right-angled stem32 turnably mounted in one of the ears such as 28 and having threadedengagement with the other of said ears such as 26. When the clampinglever 30 is turned in one direction manually it permits the ears 26 and28 to spread apart slightly so that the sleeve 20 may gagement of itsstem 32 causes the ear 26 to be drawn toward the ear 28 so that thesplit tubular member is clamped tightly upon the sleeve 20 and rotarymovement of the latter member is prevented.

Rotatably mounted in the casing 12 and extendingwithin and substantiallythroughout the length of the sleeve 20 is an arbor 34. The arbor 34 isformed with a reduced journalv 36 which is mounted for rotation in abearing 38 in the removable end member 14 ofthe casing.

A prime mover such as an electric motor 40 is mounted on the base l0 andits armature shaft 42 is operatively connected by a coupling sleeve 44with the journal 36 of the arbor.

'I'he interior wall of the sleeve 20 and the exterior surface of thearbor 34 provide the two elongated coacting surfaces which constitute adistinctive feature of my invention. As here shown, the interior surfaceof the sleeve 20 is truly cylindrical while the outer surface of thearbor 34 is slightly tapered. In other words, the arbor 34 fits quiteclosely within the sleeve 20, but is spaced a slightly greater distancetherefrom at its outer than its inner end, thus providing a convergingannular space between these members.

This arrangement, whereby a slightly tapered member is mounted withinand slightly spaced from a member having an internal cylindricalsurface,.also permits of' some adjustment of the relative spacing of thetwo Lsurfaces by adjusting the members axially. This adjustment isaccomplished, as previously indicated, by the threaded mounting of thesleeve 20 within the casing 12 and its-.extension 18.and the adjustmentwhen made is maintained by means of the clamping lever 30.

'I'he arbor 34 is formed at its inner end with a peripheral ange 46which rotates in substantial contact with the inner face of the casingend member 14 and is normally spaced somewhat from the inner end of thesleeve 20.

IThe arbor 34 is formed at its outer end wit an outwardly opening recessor cavity 48, which preferably is of substantially frusto-conical shapeand formed with a long and gradual taper; An inlet tube 50 is threadedlymounted through the outer end of the sleeve 20 and has its inner endprojecting a substantial distance within the recess 48 of the arbor. v

The outer end of the inlet tube 50 is suitably connected, as by means ofa packing gland 52, with a Y 54, the two branches of which areconnected, as by means of packing glands 56 and 58, with feed pipes 60and 62 respectively.

The two substances to be acted upon, namely the liqueous bitumen and theemulsier, are supplied to the machine through the feed pipes 60 and 62from suitable containers, which are not shown in connection with thisparticular form.

of machine although they are shown in the machine illustrated in Figure5. These containers may be in the nature of pressure tanks, whereby thesubstances may be introduced to the machine under pressure and theyshould also be equipped with means for preheating the substancesseparately to the desired temperatures.

In lieu of or in addition to pressure at the supply end, either bypressure in the supply tanks or by means of pumps communicating with thesupply pipes, the substances in the machine may be subjected to suctionor pulling force at the outlet end of the machine for causing them totravel therethrough.

The amount and rapidity of fiow of the two substances through thepipes60 and 62 may also be varied and controlled by suitable controllingmeans such as valves and/or flow meters, not shown in connection withthe present form of the machine.

The two substances, namely the liqueous bitumen and the emulsier, arethus introduced through the pipes 60 and .62 to the Y 54, whichconstitutes a closed, confined receiving or mix-v ing chamber in thepresent form of the machine.

At the instant when the bitumen meets the emulsier there is a foamingaction which greatly increases the volume of the mixture and spreads thebitumen into thin films, forming a coarse or a rough emulsion with thebitumen as the external phase-in other words, drops of emulsifiersurrounded by films of bitumen constituting a primary emulsion. Thefoaming,

frothing action serves to stretch the films of bitumen. The primaryemulsion is then immediately removed from the zone of formation and issubjected to agitation whereby the films o f bitumen are broken up intominute particles and are. thoroughly dispersed and diffused. Thisproduces a coarse or rough emulsion with the bitumen as the internalphase. In other words, the emulsion is inverted and this secondaryemulsion consists of particles of bitumen surrounded by lms of theemulsier.

Due to the forces which cause the substances to travel through themachine, the primary emulsion is immediately carried out of the Y 54 or'fil mixing chamber through the pipe and is received into the recess 48of the arbor 34. The emulsion is then forced .to travel in a reversedirection out of said recess and around the end of the tube 50, which issufficiently spaced from 'the walls of the recess`to permit such outwardtravel'without'clogging or excessive back pressure.

It willbe understood that the forcible introduction of the primaryemulsion to the recess 48 and its removal therefrom by reverse travelcauses considerable agitation of the substance so that the emulsionbecomes inverted to form a relatively coarse internal phase emulsion, orin other words,

.particles of bitumen surrounded by av film of emulsier.

The coarse or secondary emulsion with bitumen as the internal phase isnow caused to travel through the close elongated space between thesurfaces of the sleeve 20 and the arbor 34, the latter member beingrotated by its connections with the motor40. 'Ihese coacting surfacesact to stretch, sub-divide, roll and spread the particles of bitumenthrough the emulsier, and thus'form a tertiary emulsion. The spacebetween these surfaces is such as tofpromote the stretching,sub-dividing, spreading, rolling, diffusing and mixing action, and tothat lend the surfaces maybe suitably serrated or otherwise deformed orroughened.

The fineness and uniformity of the nished product is controlled toAconsiderable extent, both by the size and character of the space betweenthe surfaces and by the speed of the movement of )the surfaces withrespect to each other. It is desirable to have the annular space betweenthese surfaces slightly tapered from front to rear so that there is aconstant decrease in the space between the surfaces as the emulsionpasses between them: This is accomplished by the tapered' formation ofthe arbor 34 and it may be regulated by longitudinal adjustment of thesleeve 20. its end by a combined closing plate and bearing .Upon leavingthe annular space between the surfaces the emulsion is dischargedagainst the face of the peripheral fiange 46 of the arbor and is thrownoutwardly by centrifugal force toward the wall of the casing 12. Thisaccomplishes a re-mixing action and also causes the entrapped air to bereleased so as to render the emulsion more liquid. This centrifugalaction also tends to exert a pull on the emulsion stream, thusincreasing flow. u

The emulsion is then discharged from the casing 12 through asubstantially tangential outlet 70 located at the bottom of the casing.From the outlet the emulsion may be received into any suitablereceptacle or container where it prefer-- ably is rapidly cooled tonormal temperature, by any suitable means, to increase stability, afterwhich it is ready to be stored or shipped.

After the emulsion has reached this condition' it is, and remains, moreuniform and stable through any of the usual conditions of handling,.shipping or storing than any of the emulsions of which I know, and willstill break down from the emulsion form when spread into thin films, inshorter time and under conditions which are most desirable from thestandpoint of practical use. Moreover, the characteristics of thebitumen are not substantially altered, unless this is done deliberately,and the relative volumes of the materials making up the emulsion remainconstant throughout the process carried on by the operation of thismachine.

I purposely make use of the formation of the original or primary bitumenexternal phase emulsion because I have found that this is advantageousin breaking the bitumen into films, and that the formation of this lm inthe thinnest -form is facilitated by producing this primary emulsion ata preferred combining temperature. Proper regulation of combiningtemperature will produce maximum frothing or 'foaming action, and thusmaximum thinness of the film. By producing thinner film at this stage,the amount of grinding necessary for securing any necessary neness ofparticles. is reduced, and the requisite flneness is secured with morecertainty'.

The immediate removal of the emulsion from the zone of formation beforethe bitumen can agglomerate and bringing about the inversion of phase'without changing the relative proportions of the ingredients, is alsoimportant.

vThen by causing the secondary emulsion to pass between the elongatedsurfaces forthe grinding action, the coarse emulsion will be changed toone of finer form. The passing of the material between converging movingsurfaces causes a greater'variation of sizes than would otherwiseresult, thus making for low voidage between bitumen particles andpermitting maximum bitumen content as well as making for minimum surfacearea and thereby permitting the use of a minimum of emulsier. Theseresults are attained without sacrifice 'of uidity.

In the form shown in Figures 4, 5 and 6, like parts are designated bythe same numerals, except as otherwise indicated.

In this form two frusto-conical coacting surfaces are employed, the onebeing the internal PSW of a portion 72 of the casing, and the/ othereing the external surface of an arbor member 74 plined on the Aarborshaft 36. y

Inlgs type of machine a chamber 76 is formed at th itial end of themachine itself, this cham` ber being of cylindrical form and beingclosed at member 78, which providesa bearing at one` end of the shaft 36and is held in place by means of cap screws 80.

In Figure 5 there are shown the two pressure 5 containers for theliqueous bitumen and the emulsifier, these containers being designatedby the numerals 82 and 84. From the containers pipes 86 and 88 lead toand communicate with opposite sides of the chamber 76 of the machine andare l equipped with suitable controlling valves designated as 90 and` 92respectively.

The two liqueous substances are introduced at proper temperatures and insuitable quantities as controlled by the valves 90 and 92 to the lchamber 76 where the primary orexternal phase emulsion is formed.

The space at the initial end of the chamber 76 or adjacent to the inletmeans 90 and 92, constitutes the zone of formation within. which foamingaction of substances takes place and the primary emulsion is formed, andfrom which it is immediately withdrawn and subjected to agitation. Thisis accomplished by'a spiral blade 94 on the 'shaft 36 in the terminalportion of the cylindrical chamber 76.

Ihis agitation causes the inversion of the external phase emulsion to aninternal phase emulsion of coarse form, and this secondary emulsion isreduced by the coacting surfaces of the members 72 and 74 to the fineemulsion 4of the final or ztertiary form.

The centrifugal action upon the emulsion is produced by a plate 96splined to the shaft 36 within the enlarged cylindrical portion 14 ofthe machine. As here shown, the plate 96 is spaced from thefrusto-conical arbor member 74 and is provided with a series of fins 98on its adjacent face which serve to cause rapid forward movement andamplified centrifugal action on the emulsion emerging from the annularspace between the surfaces.

1t will be noted from Figure 4 that the taper to produce a convergenceof the space between these members. The spacing between these coactingsurfaces may be adjusted by means of an adjust-ing'nut 100 on the shaft36 threaded into a boss 102 on the end plate 14 and bearing at its innerend against the centrifuging plate 96. A

lock nut 104 is provided for fixing and holding the adjustment whenmade.

If desired, a universal joint of common form,

designated generally by the numeral 106 may be interposed between themotor shaft 42 and the arbor shaft 36 for the purpose of compensatingfor variation in alignment of the shafts and also for permitting aslight longitudinal adjustment of the shaft 36 by means of the adjustingnut 100.

It may also be desirable to provide means for maintaining thetemperature of the machine and particularly of the* substances thereinat a relatively high point and for that purpose I have o5 formed thewalls of the machine, including the mixing chamber '76, the taperedportion 72 and the enlarged cylindrical portion 12, with a jacket- 108to which live steam may be introduced by means of a pipe 110. (SeeFigure 6.) Water of condensation may be removed from the steam jacketthrough an exhaust pipe 11.2, located near the discharge 70 forthe-bitumen.

` In the form shown in Figure 'I the machine is quite similar to thatjust described, but the chamber to which the liqueous substances areintroducedl is considerably elongated and is designated by thenumeral114.

` In this form the supply pipes 86 and 88 preferably are not intransverse alignment. The pipe 88 through which the emulsifier, entersis located at the extreme initial end of the chamber 114, while the pipe86 for the liqueous bitumen is spaced longitudinally therefrom asuitable distance.l Mounted on theshaft 36 within the chamber 114 is aninterrupted spiral blade.4 The initial portion of this blade isdesignated by the numeral and it acts as a wiper for the purpose ofremoving the liqueous substances from the outlets of the pipes 88 and 86which are located respectively at the opposite ends of the blade Inother words, the wiper blade 95 takes alternate quantities of emulsierand liqueous bitumen and causes them to be mixed in the initial end ofthe chamber. It serves to keep clear the outlets tothe supply pipes andequalizes the quantities of liqueous substance going to form the primaryemulsion.

The second and longer portion of the spiral is an agitating blade spacedfrom the first blade 95 and designated by the numeral 116. The blade 116acts upon the emulsion after it leaves the initial end of the chamberand causes a thorough andv complete agitation for completelytransforming the emulsion into the secondary stage before it passes tothe 'annularv space between the surfaces of the'members '72 and 74. Inother Words, `provision is made inthe elongated chamber 114 forequalizing the quantities of liqueous substances and for more thoroughlyagitating the emulsion before it is subjected to the grinding' andtearing actionof the coacting surfaces.

In Figure 8 there is shown a machine including a base 10 upon which ismounted an elongated tapered casing 118 within which an arbor shaft 36is arranged for rotation. At the initial or smaller end of the casing118 are arranged the supply pipes 86 and 88 for introducing the liqueoussubstances.

Formed on or fixed to the shaft 36 is a tapered member designatedgenerally by the numeral 120 and this member combines the functions ofagi- ,tating the emulsion and furnishing the coacting grinding surfaces.

The member 120 has a spiral formation throughout a considerable portionof its length, whereby there are produced relatively narrow spiralsurfaces 122 coacting with the inner surface of the casing 118 and alsoa spirally arranged recess 124. The spiral surface 122 preferablyapproaches gradually more closely to the inner surface of the casingmember to produce the converging surfaces which have been previouslydiscussed at considerable length.

The spiral recess 124 begins at a point spaced suitably from the supplypipes 86 and 88 and gradually decreases in depth toward the larger endof the rotating or arbor member 120 The initial end of the casing 118serves as a small substantially closed mixing chamber for the liqueousbitumen'and the emulsier, wherein is formed the primary or externalphase emulsion. The primary emulsion is immediately acted upon andwithdrawn from the mixing chamber and is agitated by the rotating spiralportion oi' the member 120 for inverting it to the secondary phaseemulsion.

The emulsion as it travels through the casing 118 is subjected not onlyto agitation but also to the grinding action between the surfaces 122and angles to that of the member 1.30.

surfaces for the spiral portion A122, and in addi- I tion they may beutilized either for retarding or accelerating the ow of emulsion,depending upon the directionpf rotation of the member and the directionof inclination of said grooves, as will be readily understood.

Figure 9 discloses a still different type of machine` including asubstantially cylindrical casing 128 in which a rotor or arbor member130 is arranged for rotation. The member 130 is cylindrical and tssnugly within the casing 128, but is arranged slightly eccentricthereto, whereby the space between their surfaces gradually converges inthe direction of rotation and. toward the discharge port 132.

The space between the casing 128 and rotary member 130 is enlarged atone side of the machine to form an inlet and mixingchamber 134 withwhich the supply pipes 136 and 138 communicate. Preferably one of thepipes such as 136 communicates with the mixing chamber 134 slightlyin-advance of the other pipe such as 138, with respect to the directionof rotation of the member .130, so that there will be a preliminaryagitation of the substance entering through the first mentioned pipe.

The primary external phase emulsion is formed in the chamber 134 and isimmediately withdrawn therefrom by pressure or suction or both and bythe action of the rotating member 130, and is thereby agitated to formthe secondary phase emulsion of coarse form. This emulsion immediatelyproceeds through the space between the casing wall 128 and the rotatingmember 130 and is subjected to the stretching, rolling and spreadingaction which reduces it to the teritary stage before it passes throughthe outlet 132.

In this form of the machine a centrifuging plate 140 is carried anddriven by a shaft 142 arranged for rotation on an axis substantially atright The plate 140 faces the outlet port 132 of the casing and may -beformed on its face with radial fins 144 for increasing the agitation andcentrifugal action of the plate 140, which is held in place by a closingplate 146-which also provides a bearing for the shaft 142 and is securedto the casing by means of cap screws 148.

The emulsion which passes through the discharge port 132 is subjected tocentrifugal action by thev plate 140 and its ns 144 and is dischargedinto a chamber 150 from which a pipe 152 leads the emulsion to thedesired place of storage.

In Figures 10 and 11 there is shown a frusto-,

conical arbor grinding member 154 which may be substituted for thecorresponding member which is shown for instance in Figure 4. The member154, as here shown, is formed with a series of circumferentially spaced,longitudinally arranged grooves, which preferably are of angularformation. The grooves 156 open to the initial end of the memberl54'where they are of considerable depth but they decrease in depth'toward the other end of the member and prefer-v ably taper out or mergeinto the surface thereof before reaching the larger or terminal end.

` The surface of the grinding member 154 and its grooves 156 cooperatewith a coacting surface such as 158 to provide an elongated aperturethrough which the secondary emulsion iscaused to pass', as beforestated. It will be observed that on account of the progressive decreasein depthv of the grooves 156 there is provided a variation ofconvergence between coacting surfaces. That is to say, the bottoms ofthe grooves 156 will present a different degree of convergence withrespect to the surface 158 than that presented by the general surface ofthe member 154. Inasmuch as the deeper ends of the grooves 156 open tothesrnaller end of the rotating member 154, they greatly facilitate theintroduction of the comparatively coarse secondary emulsion to the spacebetween the surface of said member and the casing. From these groovesthe emulvsion is thrown out by centrifugal action of the rotor; againstthe smooth surface of the coact- .ing member, thereby increasing thespreading and rolling action and assisting in the opera- The decrease indepth of thel .uid material forces it toward the ends of the f slopinggrooves, insuring that the substance will be spread over a larger areaofthe coacting surfaces, and that none ofthe material will pass out of thenarrow aperture without being reduced to the vdesired state of neness.

The longitudinally extending spirally arranged groove 124 of the formshown in Figure 8 accomplishes the same function.

If desired the surface of the member 154 may be formed with a series ofkerfs or serrations opening to the'grooves 156 on the trailing edgesthereof with respect to the direction of rotation. These kerfs orserrations constitute roughened surfaces for the grinding member. Theyserve to stretch and spread the particles of emulsion traveling from thegrooves 156 to the narrower surface between members 154 and 158 as theformer member is rotated.

It has been found that a machine having the characteristics set forthherein is very eflicient for producing a bituminous emulsion possessingthe desired properties of flneness and uniformity of texture andcomplete coating and enveloping of individual particles of bitumen withthe emulsifying solution.

It is to be understood that any suitable and well known means may beemployed for varying the speed of the prime mover to obtain desiredspeed of the grinding member. f

.It should also be noted that any suitable means,

of which the steam jacket 108-is an illustration,

" rotary movement of the grinding member, which may-of course, besupplemented by pressure or suction effect applied to the liqueoussubstances aspreviously referred to.

It is important to introduce or iiow directly together the emulsiflerand liqueous bitumen under pressure, into a confined and substantiallyclosed mixing chamber which is free and clear and contains no agitatingmember. By so doing I purposely take advantage of the formation undersuch circumstances of the primary emulsion with bitumen as its externalphase, and take advantage of the foaming, frothing action thus produced,and utilize this natural phenomenon for accomplishing the first step ina continuous emul' siflcation process, namely, the formation of thinfilms rather than formation of threads. The use of continuous andsubstantial pressure behind the liquid materials is important inprocuring the foaming and frothing action for the forming of the primaryemulsion in the substantially enclosed mixing chamber, and also forimmediately removing the primary emulsion from the zone of formation.

Subjecting bituminous emulsion to centrifugal action, immediately afterits formation, is also important. This step reduces the hot emulsionfrom a foamy to more uid state, releases air and increases thoroughnessof mixing and dispersion,

. so that the emulsion be stable and remain closely approximatedrelatively moving surfaces may be of any desired shape and arrangement,and I ldo not desire to be understood as limiting myself to the specificforms herein shown and described. Furthermore, the convergence of thesurfaces may be secured in different ways, some' of which areillustrated in the various embodiments herein shown and described.

I claim as my invention:-

l. A machine for making bituminous emulsion .comprising a mixingchamber, separate means for flowing directly together into said chamberliqueous bitumen and an emulsifler, whereby there is formed a primaryemulsion with bitumen as the external phase, means for removing theemulsion from` the zone of formation and agitating it to form asecondary emulsion with bitumen asl theinternal phase, a pair ofcoacting, relatively movable surfaces between which thesecondaryemulsion is caused to pass for exerting a sub-dividing, rolling andspreading action thereon, whereby the particles arerreduced in size anddispersion is increased, and flat disk means for subjecting-the streamof emulsion to centrifugal action as it leaves the space between saidsurfaces.

2. A machine for making bituminous emulsion comprising a chamber,separate means for introducing to said chambenheated liqueous bitumenand an emulsifler whereby there is formed a primary emulsion withbitumen as the external phase, means for immediately removing saidpriary emulsion from the zone of formation and causing an agitationwhereby-it is converted to a secondary emulsion with bitumen as theinternal phase, an elongated aperture between two surfaces through whichthe emulsion is caused to pass, means for moving one surface relativeto, the other to subject the emulsion to spreading and rolling action,and a flatl disc-like member-adjacent and extending across the outlet ofsaid aperture, moving in a plane angular to the $1.15

of said aperture, for engaging the emulsion as it emerges from saidaperture and subjecting it to centrifugal action.

3. A machine for forming a bituminous emulsion comprising a casinghaving a. substantially closed mixing chamber, means for flowingdirectly togetherinto said chamber liqueous bitumen and an emulsiflerfor forming a primary emulsion with bitumen as the external phase,positive means being provided for immediately withdrawing the primaryemulsion from the zone of formation and agitating it to convert into asecondary emulsion with bitumen as the internal phase, an arbor grindingmember rotatably mounted in said casing and having a surface coactingwith the surface thereof for forming an elongated aperture through whichthe secondary emulsion is caused to pass for spreading and rolling theparticles, for reducing them and increasing dispersion, one of saidsurfaces being inclined relative to the other to produce a convergenceof the elongated aperture toward` its outlet end, and movable meansarranged transversely only of said aperture and having a face extendingacross its outlet end for subjecting the emerging emulsionto-centrifug'al action.

4. A machine for forming a bituminous emulsion comprising a casinghaving a substantially closed mixingchamber, means for flowing directlytogether into said chamber liqueous bitumen and an emulsiiier forforming a primary emulsion with bitumen as the external phase, meansbeing provided for immediatelyl withdrawing the primary emulsion fromthe zoneof formation and agitating it to convert into a secondaryemulsion with bitumen as the internal phase, an arbor grinding memberrotatably mounted in said casing and having a cylindrical surfacecoacting with the interior surface thereof for forming an elongatedcylindrical aperture through which the secondary emulsion is caused topass for spreading and rolling the particles, for reducing them andincreasing dispersion, one of said surfaces being inclined relative tothe other to produce a convergence of the elongated aperture toward itsoutlet end, saidI grinding member being formed with a groove in itssurface, which groove decreases in depth from the -initial end of themember and lengthwise of its axis, whereby a differently convergingspacing is procured with respect to said coacting surface.

5. A machine for forming 4bituminous emulsion comprising a chamber,means for introducing to said chamber liqueous bitumen and an emulsifierwhereby an emulsion is produced, a pair of surfaces producing anelongated aperture through which the emulsion is caused to travel. meansfor moving one surface relative to the other, and a rotating disktransverse of said aperture for subjecting the emulsion to centrifugalaction as it leaves said aperture.

6. A machine for making bituminous emulsion comprising a pair of closelyapproximated surfaces consisting of a vstator and a rotor, means forintroducing liqueous bitumen and an emulsiner to the space between saidsurfaces where they are subjected to a sub-dividing, spreading androlling action, and a disk having a surface extending across the outletend of said space for subjecting the emerging stream of emulsion tocentrifugal action immediately after it leaves the space between saidsurfaces.

7. A machine for making bituminous emulsion comprising a mixing chamber,separaitc inlet means for flowing directly together into said chamber,under pressure, liqueous bitumen and an emulsier, whereby there isformed a primary emulsion with bitumen as the external phase,wipingmeans moving across the respective inlet means for picking upuniform quantities of the substances to effect maximum frothing action,means for immediately removing the primary emulsion from the zone ofcommingling and causing agitation, an elongated, narrow convergingaperture between two surfaces through which the substance is caused topass, one of said surfaces being formed with a groove decreasinggradually in depth lengthwise of the axis of rotation, and a fiat diskfor moving one surface relative to the other to subject the substance tosub-dividing, rolling and spreading action.

8. A machine for making bituminous emulsion comprising a mixing chamber,separate inlet means for flowing directly together into4 said chamber,under pressure, liqueous bitumen and an emulsier, whereby there isformed a primary emulsion with bitumen as the external phase, wipingmeans moving across the respective inlet means for picking up uniformquantities of the substances to effect maximum frothing action, meansfor immediately removing the primary emulsion from the zone ofcommingling and causing agitation, an elongated, cylindrical, narrow,converging aperture between two surfaces through which the substance iscaused to pass, one of said surfaces being formed with a groovedecreasing gradually in depth lengthwise of the vaxis of rotation, meansfor moving one surface relative to the other to subject the substance tosub-dividing, rolling and spreading action, and means for subjecting thestream of emulsion to centrifugal action as it leaves the space betweensaid surfaces.

9. A machine for making bituminous emulsion comprising a mixing chamber,separate inlet means for flowing directlytogether into said chamber,under pressure, liqueous bitumen and an emulsier, whereby there isformed a primary emulsion with bitumen as the external phase,' .wipingmeans moving across the respective inlet means for picking up uniformquantities of the substances to effect maximum frothing action, meansfor immediately removing the primary emulsion from the zone ofcommingling and causing agitation, an elongated, cylindrical, narrow,converging aperture between two surfaces through which the substance iscaused to pass,

one of said surfaces being formed with a groove y decreasing graduallyin depth lengthwise of the axis of rotation, means for moving onesurface relative to the other to subject the substance to sub-dividing,rolling and spreading action, means for adjusting one surface relativeto the other to regulate the size of said aperture, and means forsubjecting the stream of emulsion to centrifugal action as it leaves thespace between said surfaces.

10. A machine for making bituminous emulsion comprising a mixingchamber, separate inlet means for flowing directly together into saidchamber, under pressure, liqueous bitumen and an emulsifier, wherebythere is formed a primary emulsion with bitumen as the external phase,means for immediately removing the primary emulsion from the zone ofcommingling and causing agitation, an elongated, cylindrical, narrow,converging aperture between two surfaces through which the substance iscaused to pass, one of said surfaces being formed with a groovedecreasing gradually in depth lengthwise of the axis of rotation, meansfor moving one surface relative to the other to subject the substance tosub-dividing, rolling and spreading action, means for adjusting onesurface relative to the other to regulate the size of said aperture, andmeans for subjecting the stream of emulsion tocentrifugal action as itleaves the space between saidI surfaces.

ll. A machine for making bituminous emulsion comprising a mixingchamber, separate inlet means for introducing to said chamber, underpressure, liqueous bitumen and an emulsifer, wiping means moving acrossthe respective inlet means for picking up uniformquantities of thesubstancesto effect maximum frothing action, an elongated, cylindrical,narrow aperture between two relatively movable surfaces through whichsaid substance is caused to pass for effecting a sub-dividing,l rollingand spreading action, and means for subjectingv the stream of emulsionto centrifugal action as it leaves the space between said surfaces. Y

LEON R. MACKENZIE.

